Over time, commercial and business centers have grown more densely populated, cars more numerous, and the value of real estate has risen. In response, parking structures have grown larger, and finding a parking space in large parking structures has become difficult and time-consuming for drivers. Furthermore, the act of circling or cruising around a large parking structure can create vehicle emissions that can negatively impact air quality, particularly inside semi-enclosed parking structures. At the same time, license plate readers (LPR) have been installed on the entrances and exits of many parking structures in order to improve security and parking compliance.